IDT IDT70121L55JG High-speed 2k x 9 dual-port static ram with busy & interrupt Datasheet

IDT70121S/L
IDT70125S/L
HIGH-SPEED
2K x 9 DUAL-PORT
STATIC RAM
WITH BUSY & INTERRUPT
Features
◆
✵
◆
◆
High-speed access
– Commercial: 25/35/45/55ns (max.)
– Industrial: 35ns (max.)
Low-power operation
– IDT70121/70125S
Active: 675mW (typ.)
Standby: 5mW (typ.)
– IDT70121/70125L
Active: 675mW (typ.)
Standby: 1mW (typ.)
◆
◆
◆
◆
◆
◆
◆
◆
Fully asychronous operation from either port
MASTER IDT70121 easily expands data bus width to 18 bits or
more using SLAVE IDT70125 chip
On-chip port arbitration logic (IDT70121 only)
BUSY output flag on Master; BUSY input on Slave
INT flag for port-to-port communication
Battery backup operation—2V data retention
TTL-compatible, signal 5V (±10%) power supply
Available in 52-pin PLCC
Industrial temperature range (–40°C to +85°C) is available for
selected speeds
Green parts available, see ordering information
Functional Block Diagram
OEL
OER
CEL
R/WL
CER
R/WR
I/O0L- I/O8L
I/O0R-I/O8R
I/O
Control
I/O
Control
(1,2)
(1,2)
BUSYL
A10L
A0L
BUSYR
Address
Decoder
MEMORY
ARRAY
11
CEL
OEL
R/WL
Address
Decoder
A10R
A0R
11
ARBITRATION
INTERRUPT
LOGIC
(2)
INTL
CER
OER
R/WR
INTR
(2)
2654 drw 01
NOTES:
1. 70121 (MASTER): BUSY is non-tri-stated push-pull output.
70125 (SLAVE): BUSY is input.
2. INT is non-tri-stated push-pull output.
APRIL 2006
1
©2006 Integrated Device Technology, Inc.
DSC 2654/10
IDT70121/IDT70125
High-Speed 2K x 9 Dual-Port Static RAM with Busy & Interrupt
Industrial and Commercial Temperature Ranges
Description
feature, controlled by CE, permits the on-chip circuitry of each port to enter
a very low standby power mode.
The IDT70121/IDT70125 utilizes a 9-bit wide data path to allow for
Data/Control and parity bits at the user’s option. This feature is especially
useful in data communications applications where it is necessary to use a
parity bit for transmission/reception error checking.
Fabricated using IDT’s CMOS high-performance technology, these
devices typically operate on only 675mW of power. Low-power (L)
versions offer battery backup data retention capability with each port
typically consuming 200µW from a 2V battery.
The IDT70121/IDT70125 devices are packaged in a 52-pin PLCC.
The IDT70121/IDT70125 are high-speed 2K x 9 Dual-Port Static
RAMs. The IDT70121 is designed to be used as a stand-alone 9-bit DualPort RAM or as a “MASTER” Dual-Port RAM together with the IDT70125
“SLAVE” Dual-Port in 18-bit-or-more word width systems. Using the IDT
MASTER/SLAVE Dual-Port RAM approach in 18-bit-or-wider memory
system applications results in full-speed, error-free operation without the
need for additional discrete logic.
Both devices provide two independent ports with separate control,
address, and I/O pins that permit independent, asynchronous access for
reads or writes to any location in memory. An automatic power-down
47
48
50
49
51
52
3
2
46
1
8
9
45
10
44
11
43
IDT70121/125J
J52-1(4)
12
13
14
42
41
40
52-Pin PLCC
Top View(5)
15
39
32
33
31
30
29
27
34
28
20
26
35
24
36
19
25
37
18
23
17
21
38
22
16
I/O 4L
I/O 5L
I/O 6L
I/O 7L
I/O 8L
GND
I/O 0R
I/O 1R
I/O 2R
I/O 3R
I/O 4R
I/O 5R
I/O 6R
A1L
A2L
A3L
A4L
A5L
A6L
A7L
A8L
A9L
I/O0L
I/O1L
I/O2L
I/O3L
4
7
INDEX
6
5
05/27/04
A0L
OEL
A10L
INTL
BUSYL
R/WL
CEL
VCC
CER
R/WR
BUSYR
INTR
A10R
Pin Configurations(1,2,3)
OER
A0R
A1R
A2R
A3R
A4R
A5R
A6R
A7R
A8R
A9R
I/O8R
I/O7R
.
2654 drw 02
NOTES:
1. All VCC pins must be connected to power supply.
2. All GND pins must be connected to ground supply.
3. Package body is approximately .75 in x .75 in x .17 in.
4. This package code is used to reference the package diagram.
5. This text does not indicate orientation of the actual part-marking.
2
6.42
APRIL 05, 2006
IDT70121/IDT70125
High-Speed 2K x 9 Dual-Port Static RAM with Busy & Interrupt
Industrial and Commercial Temperature Ranges
Absolute Maximum Ratings(1)
Symbol
Rating
Commercial
& Industrial
Unit
VTERM(2)
Terminal Voltage
with Respect
to GND
-0.5 to +7.0
V
TBIAS
Temperature
Under Bias
-55 to +125
o
Storage
Temperature
TSTG
IOUT
Symbol
o
-65 to +150
DC Output
Current
Recommended DC
Operating Conditions
50
C
VCC
Supply Voltage
GND
Ground
VIH
VIL
C
Parameter
Input High Voltage
Min.
Typ.
Max.
Unit
4.5
5.0
5.5
V
0
0
0
V
2.2
____
(1)
Input Low Voltage
-0.5
(2)
6.0
____
0.8
V
2654 tbl 03
NOTES:
1. VIL > -1.5V for pulse width less than 10ns.
2. VTERM must not exceed Vcc + 10%.
mA
V
2654 tbl 01
NOTES:
1. Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may
cause permanent damage to the device. This is a stress rating only and functional
operation of the device at these or any other conditions above those indicated
in the operational sections of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect reliabilty.
2. VTERM must not exceed Vcc + 10% for more than 25% of the cycle time or 10ns
maximum, and is limited to < 20mA for the period of VTERM > Vcc + 10%.
Capacitance (TA = +25°C, f = 1.0MHz)
Symbol
CIN
COUT
Parameter
Input Capacitance
Output Capacitance
Conditions(1)
Max.
Unit
V IN = 3dV
9
pF
V OUT = 3dV
10
pF
2654 tbl 04
NOTE:
1. This parameter is determined by device characterization but is not production
tested.
Maximum Operating Temperature
and Supply Voltage(1)
Grade
Commercial
Industrial
Ambient
Temperature
GND
Vcc
0OC to +70OC
0V
5.0V + 10%
0V
5.0V + 10%
O
O
-40 C to +85 C
NOTES:
1. This is the parameter TA. This is the "instant on" case temperature.
2654 tbl 02
DC Electrical Characteristics Over the Operating
Temperature and Supply Voltage Range (VCC = 5.0V ± 10%)
70121S
70125S
Symbol
Parameter
Test Conditions
(1)
70121L
70125L
Min.
Max.
Min.
Max.
Unit
|ILI|
Input Leakage Current
V CC = 5.5V, VIN = 0V to V CC
___
10
___
5
µA
|ILO|
Output Leakage Current
V CC = 5.5V, CE = VIH, VOUT = 0V to V CC
___
10
___
5
µA
0.4
___
0.4
V
___
2.4
___
V
VOL
Output Low Voltage
IOL = +4mA
___
VOH
Output High Voltage
IOH = -4mA
2.4
2654 tbl 05
NOTE:
1. At Vcc < 2.0V leakages are undefined.
3
APRIL 05, 2006
IDT70121/IDT70125
High-Speed 2K x 9 Dual-Port Static RAM with Busy & Interrupt
Industrial and Commercial Temperature Ranges
DC Electrical Characteristics Over the Operating
Temperature and Supply Voltage Range(1,4) (VCC = 5V ± 10%)
70121X25
70125X25
Com'l Only
Symbol
ICC
Parameter
Dynamic Operating Current
(Both Ports Active)
Test Condition
Version
CE = VIL, Outputs Disabled
f = fMAX(2)
ISB1
Standby Current
(Both Ports - TTL Level Inputs)
CE"A" = CE"B" = VIH
f = fMAX
ISB2
ISB3
ISB4
Standby Current
(One Port - TTL Level Inputs)
Full Standby Current (Both Ports
- CMOS Level Inputs)
Full Standby Current
(One Port - CMOS Level Inputs)
70121X35
70125X35
Com'l
& Ind
Typ.
Max.
Typ.
Max.
Unit
mA
COM'L
S
L
135
135
260
220
135
135
250
210
IND
S
L
___
___
___
___
135
135
275
250
COM'L
S
L
30
30
65
45
30
30
65
45
IND
S
L
___
___
___
___
30
30
80
65
COM'L
S
L
80
80
175
145
80
80
165
135
IND
S
L
___
___
___
___
80
80
190
165
COM'L
S
L
1.0
0.2
15
5
1.0
0.2
15
5
IND
S
L
___
___
___
___
1.0
0.2
15
5
S
L
70
70
170
140
70
70
160
130
S
L
___
___
___
___
70
70
185
160
mA
(2)
CE"A" = VIL and CE"B" = VIH(5)
Active Port Outputs Disabled,
f=fMAX(2)
CE"A" and CE"B" > VCC - 0.2V
VIN > VCC - 0.2V or
VIN < 0.2V, f = 0(3)
CE"A" < 0.2V and
CE"B" > VCC - 0.2V(5)
VIN > VCC - 0.2V or V IN < 0.2V
Active Port Outputs Disabled,
f = fMAX(2)
COM'L
IND
mA
mA
mA
2654 tbl 06a
70121X45
70125X45
Com'l Only
Symbol
ICC
Parameter
Dynamic Operating Current
(Both Ports Active)
Test Condition
Version
CE = VIL, Outputs Disabled
70121X55
70125X55
Com'l Only
Typ.
Max.
Typ.
Max.
Unit
mA
COM'L
S
L
135
135
245
205
135
135
240
200
IND
S
L
___
___
___
___
___
___
___
___
COM'L
S
L
30
30
65
45
30
30
65
45
IND
S
L
___
___
___
___
___
___
___
___
COM'L
S
L
80
80
160
130
80
80
155
125
IND
S
L
___
___
___
___
___
___
___
___
COM'L
S
L
1.0
0.2
15
5
1.0
0.2
15
5
IND
S
L
___
___
___
___
___
___
___
___
COM'L
S
L
70
70
155
125
70
70
150
120
IND
S
L
___
___
___
___
___
___
___
___
(2)
f = fMAX
ISB1
Standby Current
(Both Ports - TTL Level Inputs)
CE"A" = CE"B" = VIH
mA
(2)
f = fMAX
ISB2
ISB3
ISB4
Standby Current
(One Port - TTL Level Inputs)
Full Standby Current
(Both Ports - CMOS Level
Inputs)
Full Standby Current
(One Port - CMOS Level Inputs)
CE"A" = VIL and CE"B" = VIH(5)
Active Port Outputs Disabled,
f=fMAX(2)
CE"A" and CE"B" > VCC - 0.2V
VIN > VCC - 0.2V or
VIN < 0.2V, f = 0(3)
CE"A" < 0.2V and
CE"B" > VCC - 0.2V(5)
VIN > VCC - 0.2V or VIN < 0.2V
Active Port Outputs Disabled,
f = fMAX(2)
mA
mA
mA
2654 tbl 06b
NOTES:
1. 'X' in part numbers indicates power rating (S or L).
2. At f = fMAX, address and control lines (except Output Enable) are cycling at the maximum frequency read cycle of 1/tRC, and using “AC TEST CONDITIONS” of
input levels of GND to 3V.
3. f = 0 means no address or control lines change. Applies only to inputs at CMOS level standby.
4. Vcc=5V, TA=+25°C for Typ, and is not production tested.
5. Port "A" may be either left or right port. Port "B" is opposite from port "A".
4
6.42
APRIL 05, 2006
IDT70121/IDT70125
High-Speed 2K x 9 Dual-Port Static RAM with Busy & Interrupt
Industrial and Commercial Temperature Ranges
Data Retention Characteristics (L Version Only)
Symbol
Parameter
Test Condition
Min.
Typ.(1)
Max.
Unit
2.0
___
___
V
µA
VDR
VCC for Data Retention
ICCDR
Data Retention Current
VCC = 2V, CE > VCC - 0.2V
IND.
___
100
4000
tCDR (3)
Chip Deselect to Data Retention Time
VIN > VCC - 0.2V or V IN < 0.2
COM'L.
___
100
1500
tR(3)
Operation Recovery Time
tRC(2)
___
___
V
2654 tbl 07
NOTES:
1. VCC = 2V, TA = +25°C, and are not production tested.
2. tRC = Read Cycle Time.
3. This parameter is guaranteed but is not production tested.
Data Retention Waveform
DATA RETENTION MODE
Vcc
VDR ≥ 2V
4.5V
4.5V
tCDR
CE
tR
VDR
VIH
VIH
2654 drw 03
AC Test Conditions
Input Pulse Levels
GND to 3.0V
Input Rise/Fall Times
3ns
Input Timing Reference Levels
1.5V
Output Reference Levels
1.5V
Output Load
Figures 1 and 2
2654 tbl 08
5V
5V
1250Ω
1250Ω
DATAOUT
BUSY
INT
DATAOUT
775Ω
775Ω
30pF
5pF*
2654 drw 04
Figure 1. AC Output Test Load
Figure 2. Output Test Load
(For tLZ , tHZ , tWZ, tOW)
*Including scope and jig.
5
APRIL 05, 2006
IDT70121/IDT70125
High-Speed 2K x 9 Dual-Port Static RAM with Busy & Interrupt
Industrial and Commercial Temperature Ranges
AC Electrical Characteristics Over the
Operating Temperature and Supply Voltage Range(3)
70121X25
70125X25
Com'l Only
Symbol
Parameter
70121X35
70125X35
Com'l
& Ind
Min.
Max.
Min.
Max.
Unit
READ CYCLE
tRC
Read Cycle Time
25
____
35
____
ns
tAA
Address Access Time
____
25
____
35
ns
tACE
Chip Enable Access Time
____
25
____
35
ns
Output Enable Access Time
____
12
____
25
ns
0
____
0
____
ns
0
____
0
____
ns
____
10
____
15
ns
0
____
0
____
ns
50
____
50
ns
tAOE
Output Hold from Address Change
tOH
Output Low-Z Time
tLZ
(1,2)
Output High-Z Time
tHZ
(1,2)
Chip Enable to Power Up Time
tPU
(2)
Chip Disable to Power Down Time
tPD
(2)
____
2654 tbl 09a
70121X45
70125X45
Com'l Only
Symbol
Parameter
70121X55
70125X55
Com'l Only
Min.
Max.
Min.
Max.
Unit
Read Cycle Time
45
____
55
____
ns
tAA
Address Access Time
____
45
____
55
ns
tACE
Chip Enable Access Time
____
45
____
55
ns
tAOE
Output Enable Access Time
____
30
____
35
ns
0
____
0
____
ns
0
____
0
____
ns
____
20
____
30
ns
0
____
0
____
ns
50
____
50
ns
READ CYCLE
tRC
tOH
Output Hold from Address Change
(1,2)
tLZ
Output Low-Z Time
tHZ
Output High-Z Time (1,2)
tPU
Chip Enable to Power Up Time (2)
tPD
Chip Disable to Power Down Time
(2)
____
NOTES:
1. Transition is measured 0mV from Low or High-impedance voltage with the Output Test Load (Figure 2).
2. This parameter guaranteed by device characterization, but is not production tested.
3. 'X' in part numbers indicates power rating (S or L).
6
6.42
2654 tbl 09b
APRIL 05, 2006
IDT70121/IDT70125
High-Speed 2K x 9 Dual-Port Static RAM with Busy & Interrupt
Industrial and Commercial Temperature Ranges
Timing Waveform of Read Cycle No. 1, Either Side(1,2,4)
tRC
ADDRESS
tAA
tOH
tOH
DATAOUT
PREVIOUS DATA VALID
DATA VALID
BUSYOUT
2654 drw 05
tBDD
(3,4)
Timing Waveform of Read Cycle No. 2, Either Side(5)
tACE
CE
tAOE
(4)
tHZ (2)
OE
tHZ (2)
tLZ (1)
VALID DATA
DATAOUT
tLZ (1)
ICC
CURRENT
ISS
tPD
tPU
50%
(4)
50%
2654 drw 06
NOTES:
1. Timing depends on which signal is aserted last, OE or CE.
2. Timing depends on which signal is deaserted first, OE or CE.
3. tBDD delay is required only in a case where the opposite port is completing a write operation to the same address location. For simultaneous read operations
BUSY has no relationship to valid output data.
4. Start of valid data depends on which timing becomes effective last, tAOE, tACE, tAA, or tBDD.
5. R/W = VIH, CE = VIL, and OE = VIL, and the address is valid prior to other coincidental with CE transition LOW.
7
APRIL 05, 2006
IDT70121/IDT70125
High-Speed 2K x 9 Dual-Port Static RAM with Busy & Interrupt
Industrial and Commercial Temperature Ranges
AC Electrical Characteristics Over the
Operating Temperature and Supply Voltage Range(4)
70121X25
70125X25
Com'l Only
Symbol
Parameter
70121X35
70125X35
Com'l
& Ind
Min.
Max.
Min.
Max.
Unit
WRITE CYCLE
tWC
Write Cycle Time (4)
25
____
35
____
ns
tEW
Chip Enable to End-of-Write
20
____
30
____
ns
tAW
Address Valid to End-of-Write
20
____
30
____
ns
tAS
Address Set-up Time
0
____
0
____
ns
tWP
Write Pulse Width(6)
20
____
30
____
ns
tWR
Write Recovery Time
0
____
0
____
ns
12
____
20
____
ns
____
10
____
15
ns
0
____
0
____
ns
____
10
____
15
ns
0
____
0
____
tDW
tHZ
Data Valid to End-of-Write
Output High-Z Time
Data Hold Time
tDH
(1,2,3)
(5)
(1,3)
tWZ
Write Enable to Output in High-Z
tOW
Output Active from End-of-Write
(1,2,3,5)
ns
2654 tbl 10a
70121X45
70125X45
Com'l Only
Symbol
Parameter
70121X55
70125X55
Com'l Only
Min.
Max.
Min.
Max.
Unit
WRITE CYCLE
tWC
Write Cycle Time (4)
45
____
55
____
ns
tEW
Chip Enable to End-of-Write
35
____
40
____
ns
35
____
40
____
ns
0
____
0
____
ns
tAW
tAS
Address Valid to End-of-Write
Address Set-up Time
(6)
tWP
Write Pulse Width
35
____
40
____
ns
tWR
Write Recovery Time
0
____
0
____
ns
tDW
Data Valid to End-of-Write
20
____
20
____
ns
____
20
____
30
ns
0
____
0
____
ns
____
20
____
30
ns
0
____
0
____
tHZ
Output High-Z Time
(1,2,3)
(5)
tDH
Data Hold Time
tWZ
Write Enable to Output in High-Z(1,3)
tOW
Output Active from End-of-Write (1,2,3,5)
ns
2654 tbl 10b
NOTES:
1. Transition is measured 0mV from Low or High-impedance voltage with Output Test Load (Figure 2).
2. This parameter guaranteed by device characterization, but is not production tested.
3. For MASTER/SLAVE combination, tWC = t BAA + tWP, since R/W = VIL must occur after tBAA .
4. 'X' in part numbers indicates power rating (S or L).
5. The specified tDH must be met by the device supplying write date to the RAM under all operating conditions.
Although tDH and tOW values will vary over voltage and temperature. The actual tDH will always be smaller than the actual tOW.
6. If OE is LOW during a R/W controlled write cycle, the write pulse width must be the larger of tWP or (tWZ + tDW) to allow the I/O drivers to turn off data to be
placed on the bus for the required tDW . If OE is HIGH during a R/W controlled write cycle, this requirement does not apply and the write pulse can be as short
as the specified tWP.
8
6.42
APRIL 05, 2006
IDT70121/IDT70125
High-Speed 2K x 9 Dual-Port Static RAM with Busy & Interrupt
Industrial and Commercial Temperature Ranges
Timing Waveform of Write Cycle No. 1, R/W Controlled Timing(1,5,8)
tWC
ADDRESS
tHZ (7)
OE
tWR(3)
tAW
CE
R/W
tWP (2)
tAS(6)
tHZ
tWZ (7)
DATAOUT
(7)
tOW
(4)
(4)
tDW
tDH
DATAIN
2654 drw 07
Timing Waveform of Write Cycle No. 2, CE Controlled Timing(1,5)
tWC
ADDRESS
tAW
CE
tAS(6)
tEW (2)
tWR
(3)
R/W
tDW
tDH
DATAIN
2654 drw 08
NOTES:
1. R/W or CE must be HIGH during all address transitions.
2. A write occurs during the overlap (tEW or t WP) of a CE = VIL and a R/W = VIL
3. tWR is measured from the earlier of CE or R/W going HIGH to the end of the write cycle.
4. During this period, the I/O pins are in the output state and input signals must not be applied.
5. If the CE LOW transition occurs simultaneously with or after the R/W LOW transition, the outputs remain in the High-impedance state.
6. Timing depends on which enable signal (CE or R/W) is asserted last.
7. This parameter is determined be device characterization, but is not production tested. Transition is measured 0mV from steady state with the Output Test Load
(Figure 2).
8. If OE is LOW during a R/W controlled write cycle, the write pulse width must be the larger of tWP or (tWZ + tDW ) to allow the I/O drivers to turn off data to be
placed on the bus for the required tDW . If OE is HIGH during a R/W controlled write cycle, this requirement does not apply and the write pulse can be as short
as the specified tWP.
9
APRIL 05, 2006
IDT70121/IDT70125
High-Speed 2K x 9 Dual-Port Static RAM with Busy & Interrupt
Industrial and Commercial Temperature Ranges
AC Electrical Characteristics Over the Operating Temperature
and Supply Voltage Range(6)
70121X25
70125X25
Com'l Only
Symbol
Parameter
70121X35
70125X35
Com'l
& Ind
Min.
Max.
Min.
Max.
Unit
20
____
20
ns
BUSY TIMING (For MASTER IDT70121)
tBAA
BUSY Access Time from Address
____
tBDA
BUSY Disable Time from Address
____
20
____
20
ns
tBAC
BUSY Access Time from Chip Enable
____
20
____
20
ns
tBDC
BUSY Disable Time from Chip Enable
____
20
____
20
ns
tWDD
Write Pulse to Data Delay
(1)
50
tDDD
Write Data Valid to Read Data Delay
tAPS
Arbitration Priority Set-up Time (2)
tBDD
BUSY Disable to Valid Data
tWH
Write Hold After BUSY
(1)
60
35
(3)
(5)
45
____
5
____
____
ns
____
30
ns
15
____
30
20
____
ns
5
BUSY INPUT TIMING (For SLAVE IDT70125)
tWB
Write to BUSY Input(4)
0
____
0
____
ns
tWH
Write Hold After BUSY(5)
15
____
20
____
ns
____
50
____
60
ns
35
____
45
tWDD
tDDD
Write Pulse to Data Delay
(1)
Write Data Valid to Read Data Delay
(1)
____
ns
2654 tbl 11a
70121X45
70125X45
Com'l Only
Symbol
Parameter
70121X55
70125X55
Com'l Only
Min.
Max.
Min.
Max.
Unit
20
____
30
ns
BUSY TIMING (For MASTER IDT 70121)
tBAA
BUSY Access Time from Address
____
tBDA
BUSY Disable Time from Address
____
20
____
30
ns
tBAC
BUSY Access Time from Chip Enable
____
20
____
30
ns
tBDC
BUSY Disable Time from Chip Enable
____
20
____
30
ns
tWDD
tDDD
Write Pulse to Data Delay
(1)
70
Write Data Valid to Read Data Delay
(1)
(2)
80
55
65
5
____
5
____
ns
35
____
45
ns
tAPS
Arbitration Priority Set-up Time
tBDD
BUSY Disable to Valid Data
____
tWH
Write Hold After BUSY(5)
20
____
20
____
ns
(3)
BUSY INPUT TIMING (For SLAVE IDT 70125)
tWB
Write to BUSY Input(4)
0
____
0
____
ns
tWH
Write Hold After BUSY(5)
20
____
20
____
ns
____
70
____
80
ns
55
____
65
tWDD
tDDD
Write Pulse to Data Delay
(1)
Write Data Valid to Read Data Delay
(1)
____
NOTES:
1. Port-to-port delay through RAM cells from writing port to reading port, refer to “Timing Waveform of Write with Port-to-Port Read and BUSY.
2. To ensure that the earlier of the two ports wins.
3. tBDD is a calculated parameter and is the greater of 0, tWDD – tWP (actual) or tDDD – tDW (actual).
4. To ensure that a write cycle is inhibited on port 'B' during contention on port 'A'..
5. To ensure that a write cycle is completed on port 'B' after contention on port 'A'.
6. 'X' in part numbers indicates power rating (S or L).
10
6.42
ns
2654 tbl 11b
APRIL 05, 2006
IDT70121/IDT70125
High-Speed 2K x 9 Dual-Port Static RAM with Busy & Interrupt
Industrial and Commercial Temperature Ranges
Timing Waveform of Write with Port-to-Port Read and BUSY(1,2,3)
tWC
ADDR 'A'
MATCH
tWP
R/W'A'
tDW
DATAIN'A'
tDH
VALID
tAPS (1)
ADDR'B'
MATCH
tBDA
tBDD
BUSY'B'
tWDD
DATAOUT 'B'
VALID
(4)
tDDD
2654 drw 09
NOTES:
1. To ensure that the earlier of the two ports wins. tAPS is ignored for Slave (IDT70125).
2. CE L = CER = VIL
3. OE = VIL for the reading port.
4. All timing is the same for the left and right ports. Port 'A' may be either the left or right port. Port "B" is oppsite from port "A".
Timing Waveform of Write with BUSY(3)
tWP
R/W"A"
tWB
BUSY"B"
tWH
R/W"B"
(1)
(2)
2654 drw 10
NOTES:
1. tWH must be met for both BUSY input (slave) and output (master).
2. BUSY is asserted on port 'B' blocking R/W'B', until BUSY'B' goes HIGH.
3. All timing is the same for left and right ports. Port"A" may be either left or right port. Port "B" is the opposite from port "A".
Timing Waveform of BUSY Arbritration Controlled by CE Timing(1)
ADDR"A and B"
(1)
ADDRESSES MATCH
CE"A"
tAPS(2)
CE"B"
tBAC
tBDC
BUSY"B"
2654 drw 11
NOTES:
1. All timing is the same for left and right ports. Port “A” may be either left or right port. Port “B” is the opposite from port “A”.
2. If tAPS is not satisified, the BUSY will be asserted on one side or the other, but there is no guarantee on which side BUSY will be asserted
(70121 only).
11
APRIL 05, 2006
IDT70121/IDT70125
High-Speed 2K x 9 Dual-Port Static RAM with Busy & Interrupt
Industrial and Commercial Temperature Ranges
Timing Waveform of BUSY Arbritration Controlled by Address(1)
tRC OR tWC
ADDR'A'
ADDRESSES MATCH
ADDRESSES DO NOT MATCH
tAPS(2)
ADDR'B'
tBAA
tBDA
BUSY'B'
2654 drw 12
NOTES:
1. All timing is the same for left and right ports. Port “A” may be either left or right port. Port “B” is the opposite from port “A”.
2. If tAPS is not satisified, the BUSY will be asserted on one side or the other, but there is no guarantee on which side BUSY will be asserted
(70121 only).
AC Electrical Characteristics Over the
Operating Temperature and Supply Voltage Range(1)
70121X35
70125X35
Com'l
& Ind
70121X25
70125X25
Com'l Only
Symbol
Parameter
Min.
Max.
Min.
Max.
Unit
INTERRUPT TIMING
tAS
Address Set-up Time
0
____
0
____
ns
tWR
Write Recovery Time
0
____
0
____
ns
tINS
Interrupt Set Time
____
25
____
35
ns
tINR
Interrupt Reset Time
____
25
____
35
ns
2654 tbl 12a
70121X45
70125X45
Com'l Only
Symbol
Parameter
70121X55
70125X55
Com'l Only
Min.
Max.
Min.
Max.
Unit
0
____
0
____
ns
0
____
0
____
ns
40
____
45
ns
40
____
45
ns
INTERRUPT TIMING
tAS
tWR
tINS
tINR
Address Set-up Time
Write Recovery Time
Interrupt Set Time
____
Interrupt Reset Time
____
2654 tbl 12b
NOTES:
1. 'X' in part numbers indicates power rating (S or L).
12
6.42
APRIL 05, 2006
IDT70121/IDT70125
High-Speed 2K x 9 Dual-Port Static RAM with Busy & Interrupt
Industrial and Commercial Temperature Ranges
Timing Waveform of Interrupt Mode(1)
tWC
INTERRUPT SET ADDRESS (2)
ADDR'A'
tWR(4)
tAS(3)
R/W'A'
tINS (3)
INT'B'
NOTES:.
1. All timing is the same for left and right ports. Port “A” may be either left or right port. Port “B” is the opposite from port “A”.
2. See Interupt Truth Table.
3. Timing depends on which enable signal (CE or R/W) is asserted last.
4. Timing depends on which enable signal (CE or R/W) is de-asserted first.
2654 drw 13
Truth Tables
Truth Table I. Non-Contention Read/Write Control(4)
Left or Right Port(1)
R/W
CE
OE
D0-8
X
H
X
Z
Port Disab le and in Power-Down Mode, ISB2 or ISB4
X
H
X
Z
CER = CEL = H, Power-DownMode, ISB1 or ISB3
L
L
X
DATAIN
H
L
L
DATAOUT
H
L
H
Z
Function
Data on Port Written Into Memory (2)
Data in Memory Output on Port(3)
High-Impedance Outputs
2654 tbl 13
NOTES:
1. A0L – A10L ≠ A0R – A10R.
2. If BUSY = L, data is not written.
3. If BUSY = L, data may not be valid, see tWDD and tDDD timing.
4. 'H' = VIH, 'L' = VIL, 'X' = DON’T CARE, 'Z' = HIGH IMPEDANCE
Truth Table II. Interrupt Flag(1,4)
Left Port
Right Port
R/WL
CEL
OEL
A10L-A0L
INTL
R/WR
CER
OER
A10R-A0R
INTR
L
L
X
7FF
X
X
X
X
X
L(2)
Set Right INTR Flag
X
X
X
X
X
X
L
L
7FF
H(3)
Reset Right INTR Flag
X
X
X
X
L(3)
L
L
X
7FE
X
Set Left INTL Flag
X
L
L
7FE
H(2)
X
X
X
X
X
Reset Left INTL Flag
Function
2654 tbl 14
NOTES:
1. Assumes BUSYL = BUSYR = V IH
2. If BUSY L = VIL, then No Change.
3. If BUSY R = VIL, then No Change.
4. 'H' = HIGH,' L' = LOW,' X' = DON’T CARE
13
APRIL 05, 2006
IDT70121/IDT70125
High-Speed 2K x 9 Dual-Port Static RAM with Busy & Interrupt
Industrial and Commercial Temperature Ranges
The IDT70121/125 provides two ports with separate control, address
and I/O pins that permit independent access for reads or writes to any
location in memory. The IDT70121/125 has an automatic power down
feature controlled by CE. The CE controls on-chip power down circuitry
that permits the respective port to go into a standby mode when not selected
(CE HIGH). When a port is enabled, access to the entire memory array
is permitted.
Interrupts
If the user chooses the interrupt function, a memory location (mail box
or message center) is assigned to each port. The left port interrupt flag
(INTL) is asserted when the right port writes to memory location 7FE
(HEX), where a write is defined as the CE = R/W = VIL per Truth Table
II. The left port clears the interrupt by access address location 7FE access
when CER = OER = VIL, R/W is a "don't care". Likewise, the right port
interrupt flag (INTR) is asserted when the left port writes to memory location
7FF (HEX) and to clear the interrupt flag (INTR), the right port must access
the memory location 7FF. The message (9 bits) at 7FE or 7FF is userdefined, since it is an addressable SRAM location. If the interrupt function
is not used, address locations 7FE and 7FF are not used as mail boxes,
but as part of the random access memory. Refer to Table II for the interrupt
operation.
The BUSY outputs on the IDT70121/125 RAM in master mode, are
push-pull type outputs and do not require pull up resistors to operate. If
these RAMs are being expanded in depth, then the BUSY indication for
the resulting array requires the use of an external AND gate.
Width Expansion with Busy Logic
Master/Slave Arrays
When expanding an IDT70121/125 RAM array in width while using
BUSY logic, one master part is used to decide which side of the RAM array
will receive a BUSY indication, and to output that indication. Any number
of slaves to be addressed in the same address range as the master use
the BUSY signal as a write inhibit signal. Thus on the IDT70121 RAM the
BUSY pin is an output of the part, and the BUSY pin is an input of the
IDT70125 as shown in Figure 3.
If two or more master parts were used when expanding in width, a split
decision could result with one master indicating BUSY on one side of the
array and another master indicating BUSY on one other side of the array.
This would inhibit the write operations from one port for part of a word and
CE
MASTER
Dual Port
RAM
BUSYL BUSYR
CE
SLAVE
Dual Port
RAM
BUSYL BUSYR
DECODER
Functional Description
MASTER
CE
Dual Port
RAM
BUSYL
BUSYR
SLAVE
CE
Dual Port
RAM
BUSYR
BUSYL
BUSYR
Busy Logic
Busy Logic provides a hardware indication that both ports of the RAM
have accessed the same location at the same time. It also allows one of the
two accesses to proceed and signals the other side that the RAM is “busy”.
The BUSY pin can then be used to stall the access until the operation on
the other side is completed. If a write operation has been attempted from
the side that receives a BUSY indication, the write signal is gated internally
to prevent the write from proceeding.
The use of BUSY logic is not required or desirable for all applications.
In some cases it may be useful to logically OR the BUSY outputs together
and use any BUSY indication as an interrupt source to flag the event of
an illegal or illogical operation. If the write inhibit function of BUSY logic is
not desirable, the BUSY logic can be disabled by using the IDT70125
(SLAVE). In the IDT70125, the BUSY pin operates solely as a write inhibit
input pin. Normal operation can be programmed by tying the BUSY pins
HIGH. Once in slave mode the BUSY pin operates solely as a write inhibit
input pin. If desired, unintended write operations can be prevented to a
port by tying the BUSY pin for that port LOW.
BUSYL
,
2654 drw 14
Figure 3. Busy and chip enable routing for both width and depth
expansion with 70121 (Master) and 70125 (Slave) RAMs.
inhibit the write operations from the other port for the other part of the word.
The BUSY arbitration, on a master, is based on the chip enable and
address signals only. It ignores whether an access is a read or write. In
a master/slave array, both address and chip enable must be valid long
enough for a BUSY flag to be output from the master before the actual write
pulse can be initiated with either the R/W signal or the byte enables. Failure
to observe this timing can result in a glitched internal write inhibit signal and
corrupted data in the slave.
14
6.42
APRIL 05, 2006
IDT70121/IDT70125
High-Speed 2K x 9 Dual-Port Static RAM with Busy & Interrupt
Industrial and Commercial Temperature Ranges
Ordering Information
IDT XXXXX
X
XXX
X
Device Power Speed Package
Type
X
X
Process/
Temperature
Range
Blank
I (1)
Commercial (0°C to +70°C)
Industrial (-40°C to +85°C)
G
Green
J
52-pin PLCC (J52-1)
25
35
45
55
Commercial Only
Commercial & Industrial
Commercial Only
Commercial Only
L
S
Low Power
Standard Power
70121
18K (2K x 9-Bit) MASTER Dual-Port RAM
w/ Interrupt
18K (2K x 9-Bit) SLAVE Dual-Port RAM
w/ Interrupt
2654 drw 15
70125
,
Speed in nanoseconds
NOTE:
1. Industrial temperature: for other speeds, packages and powers contact your sales office.
Datasheet Document History
01/06/99:
06/03/99:
05/28/04:
04/05/06:
Initiated datasheet document history
Converted to new format
Cosmetic and typographical corrections
Pages 2 and 3
Added additional notes to pin configurations
Changed drawing format
Page 1
Corrected DSC number
Page 3
Changed storage temperature parameter from -55 to +125 to -65 to +150
Clarified TA parameter footnote
Page 4
DC Electrical parameters–changed test condition wording from "open" to "disabled"
Page 9
Changed ±500mV to 0mV in notes
Page 2
Added date revision for pin configuration
Page 4, 6, 8,10&12 Added Industrial temp to column headings for 35ns speed to DC and AC Electrical Characteristics
Page 4
Removed Industrial temp from 25, 45 & 55ns speeds from DC Electrical Characteristics
Page 3, 4, 6, 8,10&12 Removed Industrial temp footnote from all tables
Page 10
Corrected error in AC BUSY timing tables changing 71V33 to 70121 and changing 71V43 to 70125
Page 15
Added Industrial temp offering to 35ns ordering information
Page 1 & 15
Replaced old TM logo with new TM logo
Page 6
Footnote reference 5 removed from AC Electrical Characteristics READ table
Page 1
Changed wording of footnote 1 from "INT is totem-pole output" to "INT is non-tr-stated push-pull output"
Page 5
Updated AC Test Conditions Input Rise/Fall Times from 5ns to 3ns
Page 1
Added green availability to features
Page 15
Added green indicator to ordering information
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15
APRIL 05, 2006
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